1. Technical Field
The present invention relates to a piezoelectric vibrator element and a piezoelectric vibrator, and in detail to an excitation electrode for exciting a vibrating arm part.
2. Related Art
For example, in the electronic apparatus such as a cellular phone or a portable information terminal, a piezoelectric vibrator using a quartz crystal or the like is used as a device used for a clock time source, a timing source for a control signal and so on, a reference signal source, and so on. As a piezoelectric vibrator of this kind, there has been known a device having a piezoelectric vibrator element hermetically encapsulated in a cavity formed of a package and a lid member as shown in JP-A-2015-97364 (Document 1).
Conventional piezoelectric vibrator elements are each provided with a base, which is formed of a piezoelectric material and has a predetermined length, and a pair of vibrating arms extending side by side from the base, and at the same time, provided with a pair of fixing arms extending side by side from both side ends of the base on the outer sides of the vibrating arms.
By fixing the piezoelectric vibrator element to the package with the fixing arms, the distance from the vibrating arms to the fixation part via the base is made long, and thus, it is possible to suppress the vibration leakage from the fixation part.
Incidentally, the piezoelectric vibrator element is miniaturized due to a requirement from an electronic apparatus equipped with the piezoelectric element.
However, the sum of the lengths of the base and the vibrating arm corresponds to the total length of the piezoelectric vibrator element, and if the base is shortened for the miniaturization, the distance to the fixation part via the base decreases to weaken the suppression effect of the vibration leakage, and if, in contrast, the length of the base is increased, the miniaturization cannot be achieved.
In the technology described in Document 1, regarding the connection between a base 31 and support arms 36, 37, there is adopted a structure in which a connection part 35 is formed on a surface on an opposite side to the side on which vibrating arms 32, 33 are formed, instead of a side surface of the base 31, and the connection part 35 and the support arms 36, 37 are connected to each other with a coupling part 34.
Therefore, it results that the vibration from the vibrating arms 32, 33 is transmitted through the base 31, the connection part 35, and the coupling part 34, and it is possible to elongate the transmission path, but the connection part 35 and the coupling part 34 are formed in the longitudinal direction of the piezoelectric vibrator element, and therefore, there is a problem that the piezoelectric vibrator element grows in size as much as the length of the connection part 35 and the coupling part 34 accordingly.